Bonding process is generally adopted in the display technology field; for example, flexible printed circuit boards, which are disposed at the perimeter of a display panel, are bonded onto a display substrate (for example, an array substrate or a color filter substrate) of the display panel.
Influencing factors such as temperature, pressure and time in the bonding process can cause differences in product quality. Influencing factors can vary because of the equipment stability and the material accuracy during the product manufacture process, and then fluctuation of the product quality can be caused, and therefore, a monitoring process should be adopted to ensure the product quality.
Currently, both chips (for example, COG (Chip-On-Glass)) and peripheral circuit board (for example, FOG (FPC-On-Glass)) can be bonded onto a display substrate through the bonding process conducted on an array substrate. Because the array substrate can transmit light or partially transparent, the bonding status of COG/FOG can be easily monitored.